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Home My WebLink AboutFOOTHILLS MALL REDEVELOPMENT, MULTI-FAMILY - FDP - FDP150048 - SUBMITTAL DOCUMENTS - ROUND 2 - FIRE AUTHORITY REQUIREMENTS5285 McWhinney Blvd., Suite 160 TEL 970.461.7733 Loveland, CO 80538 FAX 970.635.3709 www.olssonassociates.com January 22, 2016 Dan Mogen Water-Wastewater Engineering City of Fort Collins 281 North College Avenue Fort Collins, CO 80524 RE: Fire Flow Analysis Revised Major Amendment to a Portion of Foothills Mall Redevelopment Planning Area 3 (Lots 3, 4, 5, and 6 of Foothills Mall Redevelopment Dear Mr. Mogen Since two areas within the development will have dead-end mainlines, fire flow analysis was completed to determine residual pressure at each dead end during the fire flow. The calculations are based on a fire flow test conducted on July 10, 2015. Please note the results were provided to Olsson. I did not observe the fire flow test. See Exhibit B Fire Flow Test Results. Based on the results an initial static pressure of 76 pounds per square inch was measured at a fire hydrant as shown on page 3 of Exhibit B. The elevation at the location of the fire hydrant was assumed to be 5016 feet. The 2012 International Fire Code was referenced to determine the fire flow requirements for the buildings served by the dead end water lines. From those requirements hydraulic calculations were completed to determine the residual pressure at the dead end. The following tables summarize the requirements and calculations. Table 1: Fire Flow Requirements Description Building Served Building Type Sprinkler System Gross Area (sq-ft) Fire Flow (gpm) Allowed Reduction Required Fire Flow (gpm) Dead End 1 Building 1 VB NFPA 13 20,199 3,750 75% 1,500 Dead End 2 Building 19 VA NFPA 13 91,907 5,500 75% 1,500 Table 2: Hydraulic Calculations Description Size Pipe Type Pressure at Mainline Loop Connection (Pressure 1, psi) Flow (gpm) Resulting Residual Pressure (Pressure 2, psi) Dead End 1 8-inch PVC 81 1,500 74 Dead End 2 8-inch PVC 77 1,500 74 Fire Flow Analysis Major Amendment to a Portion of Foothills Mall Redevelopment Planning Area 3 (Lots 3, 4, 5, and 6 of Foothills Mall Redevelopment Page 2 In conclusion, the calculations indicate the residual pressures will be far above the recommended residual fire flow pressure of 20 pounds per square inch. The following supporting materials are attached for reference: • Exhibit A – Vicinity Map • Exhibit B – Fire Flow Test Results • Exhibit C – Dead End 1 Details • Exhibit D – Dead End 2 Details • Exhibit E – Dead End 1 Hydraulic Calculations • Exhibit F – Dead End 2 Hydraulic Calculations • 2012 International Fire Code - Appendix B - Fire-Flow Requirements for Buildings If you have any questions or need additional information, please contact me. Sincerely, Olsson Associates Daniel Hull, PE Senior Project Engineer Enclosures R TEL 970.431.7733 Loveland, CO 80538 Suite 160 5285 McWhinney Boulevard LOT 8 + VAC TULANE PORTION LOT 1 + VAC TULANE PORTION LOT 1 + LOT 2 Foothills Mall Multi-Family Lot 3 Lot 4 Lot 5 Lot 6 12/12/2015 Exhibit A Vicinity Map Dead End 2 Dead End 1 Location of Fire Hydrant Static Pressure Exhibit B Fire Flow Test Results (Page 1 of 4) Exhibit B Fire Flow Test Results (Page 2 of 4) Exhibit B Fire Flow Test Results (Page 3 of 4) Exhibit B Fire Flow Test Results (Page 4 of 4) TEL 970.431.7733 Loveland, CO 80538 Suite 160 5285 McWhinney Boulevard R T T AREA INLET TYP. SANITARY MANHOLE SANITARY MANHOLE STORM MANHOLE STORM MANHOLE PROPOSED FIRE HYDRANT AREA INLET TYP. 39.1 L.F. OF 12" STORM 36.7 L.F. OF 12" STORM STORM MANHOLE EXISITING 8" WATER MAIN EXISTING 10" WATERLINE 1.5" SERVICE METER PIT 1.5" SERVICE METER PIT 1.5" SERVICE METER PIT 1.5" SERVICE METER PIT 110.0 L.F. OF 18" STORM 106.1 L.F. OF 18" STORM 111.9 L.F. OF 18" STORM 110.1 L.F. OF 24" STORM 382.5 L.F. OF 6" SANITARY SEWER MAIN 121.0 L.F. 4" FIRE SERVICE 110.3 L.F. 4" FIRE SERVICE 115.3 L.F. 1.5" WATER SERVICE 36.3 L.F. 1.5" WATER SERVICE 36.3 L.F. 4" FIRE SERVICE 121.0 L.F. 1.5" WATER SERVICE 335.0 L.F. 8" WATER MAIN 15.0 L.F. OF 6" SANITARY SEWER SERVICE 16.0 L.F. OF 6" SANITARY SEWER SERVICE 15.9 L.F. OF 6" SANITARY TEL 970.431.7733 Loveland, CO 80538 Suite 160 5285 McWhinney Boulevard R Exhibit D Dead End 2 Details Pressure 1: Elevation 5014' Static Pressure 77 psi Pressure 2: Elevation 5015' Dead End 2: Length 163' Size 8-inch Type = PVC Foothills Mall Multi-Family 135 ft 28 ft R TEL 970.431.7733 Loveland, CO 80538 Suite 160 Exhibit E Dead End 1 5285 McWhinney Boulevard Hydraulic Calculations Project Description Friction Method Hazen-Williams Formula Solve For Pressure at 2 Input Data Pressure 1 81 psi Elevation 1 5005 ft Elevation 2 5009 ft Length 348 ft Roughness Coefficient 130 Diameter 8 in Discharge 1500 gal/min Results Pressure 2 74 psi Headloss 13.47 ft Energy Grade 1 5193.52 ft Energy Grade 2 5180.04 ft Hydraulic Grade 1 5192.09 ft Hydraulic Grade 2 5178.62 ft Flow Area 0.35 ft² Wetted Perimeter 2.09 ft Velocity 9.57 ft/s Velocity Head 1.42 ft Friction Slope 0.03872 ft/ft Dead End 1 Hydraulic Calculations Foothills Mall Multi-Family R TEL 970.431.7733 Loveland, CO 80538 Suite 160 Exhibit F Dead End 2 5285 McWhinney Boulevard Hydraulic Calculations Foothills Mall Multi-Family Project Description Friction Method Hazen-Williams Formula Solve For Pressure at 2 Input Data Pressure 1 77 psi Elevation 1 5014 ft Elevation 2 5015 ft Length 163 ft Roughness Coefficient 130 Diameter 8 in Discharge 1500 gal/min Results Pressure 2 74 psi Headloss 6.31 ft Energy Grade 1 5193.03 ft Energy Grade 2 5186.72 ft Hydraulic Grade 1 5191.61 ft Hydraulic Grade 2 5185.30 ft Flow Area 0.35 ft² Wetted Perimeter 2.09 ft Velocity 9.57 ft/s Velocity Head 1.42 ft Friction Slope 0.03872 ft/ft Worksheet for Dead End 2 SEWER SERVICE 15.6 L.F. OF 6" SANITARY SEWER SERVICE TRANSFORMER TRANSFORMER TRANSFORMER TRANSFORMER BUILDING 1 TYPE D3 BUILDING 2 TYPE C3 BUILDING 3 TYPE E2 BUILDING 4 TYPE D2 INSTALL 4" TAP W/ VALVE AND THRUST BLOCK INSTALL 4" TAP W/ VALVE AND THRUST BLOCK INSTALL 4" TAP W/ VALVE AND THRUST BLOCK INSTALL 4" TAP W/ VALVE AND THRUST BLOCK INSTALL 1.5" TAP INSTALL 1.5" TAP INSTALL 1.5" TAP INSTALL 1.5" TAP 18.0 L.F. 1.5" WATER SERVICE 18.0 L.F. 4" FIRE SERVICE 116.6 L.F. 8" WATER MAIN 7.6 L.F. 8" WATER MAIN SANITARY MANHOLE PROPOSED FIRE HYDRANT Exhibit C Dead End 1 Details 348 ft Pressure 1: Elevation 5005 Static Pressure 81 psi Pressure 2: Elevation 5009 Dead End 1: Length 348' Size 8-inch Type = PVC Foothills Mall Multi-Family